This application claims priority to an application entitled xe2x80x9cControl Method for Driving Backlight Parts in Mobile Phonexe2x80x9d filed in the Korean Industrial Property Office on Aug. 19, 2000 and assigned Serial No. 2000-48159, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to a mobile phone, and in particular, to a control method for driving backlight parts to provide a backlight to a display and a keypad.
2. Description of the Related Art
In general, a mobile phone has a backlight function that allows a user to identify information on a display and keys on a keypad. Thus, the mobile phone includes a display backlight part for providing backlight to a display, such as an LCD (Liquid Crystal Display), and a keypad backlight part for providing backlight to the keypad. Typically, an EL (Electroluminescence Element) is used to display the backlight part and an LED (Light Emitting Diode) is used to display the keypad backlight part. The display backlight part and the keypad backlight part are driven, according to the state of the mobile phone.
FIG. 1 is a block diagram of a mobile phone, mainly illustrating parts related with driving backlight parts. Referring to FIG. 1, an RF (Radio Frequency) module 100 processes an RF signal and transmits/receives the RF signal under the control of a controller 106. A keypad 102 is provided with a plurality of digit keys and function keys and transmits data corresponding to key input to the controller 106. A cover monitor 104 senses the closing and opening of a flip cover or a folder cover and notifies the controller 106 of the cover state. The controller 106 turns ON or turns OFF a display backlight part 108 and a keypad backlight part 110, according to the key data received from the keypad 102, depending on the cover state data received from the cover monitor 104.
The method for driving the display backlight part 108 and the keypad backlight part 110 will be described in FIG. 2.
In step 200, the controller 106 determines whether key input data has been received or, if the cover is opened. Upon receipt of the key input data from the keypad 102, or upon receipt of information indicating that the cover has been opened from the cover monitor 104, the controller 106 turns ON both the display backlight part 108 and the keypad backlight part 110 in step 202. Hence, backlight is provided to a display (not shown) and the keypad 102. In this state, the controller 106 checks whether a predetermined time has elapsed in step 204. When the predetermined time has elapsed, the controller 106 turns OFF both the display backlight part 108 and the keypad backlight part 110 in step 206, thereby preventing power dissipation caused by the long ON-state of the display backlight part 108 and the keypad backlight part 110.
In the conventional control method, as described above, the display backlight part and the keypad backlight part are turned ON at the same time when a user presses a key or opens a flip or folder cover. However, in the case that the user intends to view an RSSI (Received Signal Strength Indicator) or time on the display, he often turns ON the display backlight part just by manipulating an external key like a volume key without opening the cover. In this case, due to the mechanism of simultaneously turning ON/OFF the display backlight part and the keypad backlight part, a backlight is unnecessarily provided to the keypad when the cover is closed.
In the case of a so-called dual folder-type mobile phone having two displays, one of them is disposed on the outer surface of its folder cover to allow a user to view the display, even if the folder cover is closed, and the other display is disposed in such a way that it can be seen only when the folder cover is opened. An RSSI or time is displayed on the outer display. However, a user sometimes manipulates an external key when he wants to view the RSSI or time without opening the folder cover in the dual folder-type mobile phone, as in a flip-type mobile phone and a folder-type mobile phone, having a single display. According to the above conventional method, both backlight parts for the outer display and the inner display are turned ON even though it is not necessary to turn ON the backlight part for the inner display.
Therefore, a backlight part that is unnecessarily turned ON increases power dissipation, and as a result the life of a battery decreases.
A need exists for a method and an apparatus that enables a folder or flip-type mobile communication terminal to decide if a backlight part or a keypad backlight part should be turned ON, so the power, of the mobile communication terminal, will not be dissipated.
It is, therefore, an object of the present invention to provide a method for driving backlight parts to prevent power dissipation caused by unnecessary operation of a display backlight part and a keypad backlight part in a mobile phone.
To achieve the above object, there is provided a method for driving backlight parts to provide a backlight to a display and a keypad in a mobile terminal. The display backlight part and the keypad backlight part are controlled to be selectively driven, according to the state of the cover and the presence or absence of key input data.